Optimizing battery life and network resources during position location tracking scenario

ABSTRACT

An apparatus and method for optimizing battery life and network resources during position tracking is disclosed. The position of a target being tracked is compared with a predefined geofence boundary. If the position of the target is far from the geofence boundary, position fix of the target is calculated using low quality of service (QoS) parameters. If the position of the target is not far from the geofence boundary, position fix of the target is calculated using high quality of service (QoS) parameters.

FIELD

This disclosure relates generally to apparatus and methods for wirelesstracking of people or assets. More particularly, the disclosure relatesto optimizing battery life and network resources during positiontracking such as in geofence.

BACKGROUND

Geofence tracking is the monitoring of movement of targets such aspersonal assets, vehicles or personnel within a defined geographicboundary. Geofence tracking is used to track and record the entry andexit of an assigned target (such as a vehicle) from a geographicboundary and to alert a user of the entry and/or exit activities of theassigned target.

A target's location within the geographic location may be established byposition fixes. To obtain a highly accurate position fix, a mobilestation device (e.g., portable device) may obtain SPS (SatellitePositioning System) pseudorange measurements and calculate its positionrelative to the geofence boundary. Alternatively, ground systems such asbut not limited to Advanced Forward Link Trilateration (AFLT), RadioFrequency Identification (RFID), Bluetooth or Zigbee systems may beused. Achieving an accurate position fix using SPS pseudorangemeasurements requires the mobile station to perform complex calculationswhich can deplete the mobile station's battery power and use valuablenetwork resources (e.g., geofence network resources, mobile stationnetwork resources, etc.). As used herein, SPS pseudorange measurementsmay be from a Global Positioning System (GPS), Galileo, Russian GlobalNavigation Satellite System (GLONASS), NAVSTAR, Global NavigationSatellite System (GNSS), a system that uses satellites from acombination of these systems, or any SPS developed in the future, eachreferred to generally herein as a Satellite Positioning System (SPS). Asused herein, an SPS will also be understood to include analogousterrestrial ranging signal sources, such as pseudolites.

SUMMARY OF THE DISCLOSURE

Disclosed is an apparatus and method for optimizing battery life andnetwork resources during position tracking. According to one aspect, amethod for optimizing battery life and network resources during positiontracking comprising defining a geofence center and a geofence boundary,receiving geofence network information associated with an area definedby the geofence boundary, obtaining mobile station network information,comparing the mobile station network information to the geofence networkinformation, incrementing a skip counter if the mobile station networkinformation is not within the geofence network information, comparingthe skip counter to a maximum skip value; and, calculating a positionfix using low quality of service parameters if the skip counter exceedsthe maximum skip value.

In another aspect, a method for optimizing battery life and networkresources during position tracking comprising defining a geofence centerand a geofence boundary, receiving geofence network informationassociated with an area defined by the geofence boundary, obtainingmobile station network information, comparing the mobile station networkinformation to the geofence network information, recovering a last realposition fix if the mobile station network information is within thegeofence network information, calculating a distance radius andreferencing the distance radius to the last real position fix to definea circle, determining if the circle is far from the geofence boundary,and calculating a position fix using quality of service parameters.

In another aspect, a position tracking device comprises a processor withprogrammable instructions for defining a geofence center and a geofenceboundary and for calculating a position fix, a receiving unit forreceiving geofence network information associated with an area definedby the geofence boundary, and for receiving mobile station networkinformation, and a comparator unit for comparing the mobile stationnetwork information to the geofence network information.

In another aspect, a computer-readable medium including program codestored thereon, comprising program code to define a geofence center anda geofence boundary, program code to receive geofence networkinformation associated with an area defined by the geofence boundary,program code to obtain mobile station network information, program codeto compare the mobile station network information to the geofencenetwork information, program code to increment a skip counter if themobile station network information is not within the geofence networkinformation, program code to compare the skip counter to a maximum skipvalue, and program code to calculate a position fix using low quality ofservice parameters if the skip counter exceeds the maximum skip value.

In another aspect, a computer-readable medium including program codestored thereon, comprising program code to define a geofence center anda geofence boundary, program code to receive geofence networkinformation associated with an area defined by the geofence boundary,program code to obtain mobile station network information, program codeto compare the mobile station network information to the geofencenetwork information, program code to recover a last real position fix ifthe mobile station network information is within the geofence networkinformation, program code to calculate a distance radius and referencingthe distance radius to the last real position fix to define a circle,program code to determine if the circle is far from the geofenceboundary, and program code to calculate a position fix using quality ofservice parameters.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a geographic diagram illustrating an example situation wherebattery life and network resources can be optimized during positiontracking.

FIG. 2 is an exemplary flow diagram for optimizing battery life andnetwork resources during position tracking.

FIG. 3 illustrates an exemplary geofence center and boundary and anexemplary circle (area) created by D_(R) with the last real position fixP(t_(n-1)).

FIG. 4 illustrates an exemplary scenario in which the mobile stationdevice determines if it is “far” from the geofence edge.

FIG. 5 illustrates one aspect of a position tracking device comprising aprocessor, receiving unit, comparator unit, and skip counter.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various aspects of the presentdisclosure and is not intended to represent the only aspects in whichthe present disclosure may be practiced. Each aspect described in thisdisclosure is provided merely as an example or illustration of thepresent disclosure, and should not necessarily be construed as preferredor advantageous over other aspects. The detailed description includesspecific details for the purpose of providing a thorough understandingof the present disclosure. However, it will be apparent to those skilledin the art that the present disclosure may be practiced without thesespecific details. In some instances, well-known structures and devicesare shown in block diagram form in order to avoid obscuring the conceptsof the present disclosure. Acronyms and other descriptive terminologymay be used merely for convenience and clarity and are not intended tolimit the scope of the disclosure.

The various illustrative logical blocks, modules, and circuits describedherein may be implemented or performed with one or more processors. Aprocessor may be a general purpose processor, such as a microprocessor,a specific application processor, such a digital signal processor (DSP),or any other hardware platform capable of supporting software. Softwareshall be construed broadly to mean any combination of instructions, datastructures, or program code, whether referred to as software, firmware,middleware, microcode, or any other terminology. Alternatively, aprocessor may be an application specific integrated circuit (ASIC), aprogrammable logic device (PLD), a field programmable gate array (FPGA),a controller, a micro-controller, a state machine, a combination ofdiscrete hardware components, or any combination thereof. The variousillustrative logical blocks, modules, and circuits described herein mayalso include machine readable medium for storing software. The machinereadable medium may also include one or more storage devices, atransmission line, or a carrier wave that encodes a data signal.

FIG. 1 illustrates an example situation where battery life and networkresources can be optimized during position tracking. FIG. 1 shows threetransport carriers (first transport carrier 110, second transportcarrier 130 and third transport carrier 140) delivering packages 111(not shown) from New York, N.Y. to Los Angeles, Calif. The transportcarriers may be delivering packages 111 for the United States PostalService (“USPS”) or another transport service. In one aspect, a userdesires to track its package 111 to determine where the package 111 isand how soon the package 111 will be delivered. The user also desires toknow with great accuracy when the package 111 has arrived within apredefined geofence boundary 420. In one example, the predefinedgeofence boundary 420 encompasses Los Angeles County. Here, there is noneed for precise position location tracking while the first transportcarrier 110 carrying package 111 is still traveling outside California.When the first transport carrier 110 is very far from Los AngelesCounty, the mobile station device 1000 may delay calculating a positionfix using high quality of service (QoS) parameters for a specified timeand instead, calculates a position fix using low QoS parameters. In oneaspect, QoS refers to position determination accuracy and time-to-fix.

In the example, a second transport carrier 130 is closer to Los AngelesCounty than the first transport carrier 110, but it is still “far” fromthe geofence boundary 420. One skilled in the art would understand thatthe definition of “far” is dependent on the particular example and couldinvolve parameters set by the user. Here, a position fix is calculatedusing low QoS parameters.

In the example, a third transport carrier 140 is closer to Los AngelesCounty than the second transport carrier 130. The third transportcarrier 140 in FIG. 1 is “not far” from the geofence boundary 420. Here,calculating a position fix using low QoS parameters is inadequate toshow the third transport carrier's 140 proximity to the geofenceboundary 420. The third transport carrier's 140 position fix iscalculated using high QoS parameters.

A position fix can be obtained in a variety of modes, including but notlimited to, stand-alone Satellite Positioning Systems (SPS) with noground system assistance; MS-based (Mobile Station-based) SPS withground system assistance for initialization; MS-assisted (MobileStation-assisted) with an external entity performing the position fix;AFLT (Advanced Forward Link Trilateration) based on code divisionmultiple access (CDMA) sectors trilateration; hybrid based on SPS andCDMA sectors trilateration; and sector center based on sector location.SPS includes Global Positioning System (GPS), Galileo, GLONASS, NAVSTAR,GNSS and any system that uses satellites from a combination of thesesystems or any future developed satellite systems. As used herein, SPSwill also be understood to include analogous terrestrial ranging signalsources such as pseudolites. One skilled in the art would understandthat other modes, such as but not limited to inertial sensors, MobileSwitching Center (MSC) identification (ID), CDMA zone, roaming list,AFLT systems, RFID, Bluetooth, Zigbee, etc., for calculating theposition fix are also available. Generally, SPS position fixes have highQoS (for example, higher-accuracy and shorter time-to-fix), butcalculating position fixes using SPS requires more battery power andnetwork resources from the mobile station device 1000. The alternativemodes for calculating position fixes have low QoS (for example,lower-accuracy and longer time-to-fix) but require less battery powerand network resources from the mobile station device 1000. In oneaspect, high QoS parameters are obtained from SPS sources. In oneaspect, high QoS parameters are obtained from non-SPS sources. Inanother aspect, low QoS parameters are obtained from non-SPS sources.

FIG. 2 is an exemplary flow diagram for optimizing battery life andnetwork resources during position tracking. One skilled in the art wouldunderstand that FIG. 2 presents an exemplary combination and ordering ofthe blocks. Various other combinations and orderings of the blockspresented in FIG. 2 will be readily apparent to those skilled in the artwithout departing from the spirit or scope of the disclosure.

In Block 210, the geofence center and geofence boundary 420 are defined.The mobile station device 1000 receives a latitude, longitude and radiusto define the geofence center and boundary. The latitude, longitude andradius are all geofence system parameters that may be configured by theuser, the operator or the application itself. FIG. 3 illustrates anexemplary geofence boundary 420 based on a latitude 320, a longitude 330and a radius R 340. One of ordinary skill in the art would understandthat these geofence system parameters may change depending on the needsof the user. More generally, one skilled in the art would understandthat the geofence boundary 420 could be defined by a polygon withparameters defined by the user, operator and/or particular application.

In Block 220, the mobile station device 1000 receives a list of SystemID/Network ID (“SID/NID”) pairs and a list of cell identifications (CellID) associated with the SID/NID pairs (collectively labeled as geofencenetwork information). FIG. 2 refers to the geofence SID/NID pairs andassociated cell identifications as “G”. The SID/NID pairs list may coverone or more operators. Each list size may be zero or more entries long.The SID/NID pairs and associated cell identifications specify the listof Sectors that cover the geofence area created by the center point CP(e.g., latitude, longitude) and radius R 340 in a predeterminedgeographical area. FIG. 3 illustrates cell identifications 1 through 6intersecting an exemplary geofence boundary 420. Cell identification isa numerical identification associated with a cell within the geofenceboundary 420.

In Block 230, the mobile station device 1000 obtains its current SID/NIDpair and associated cell identification (collectively labeled as mobilestation network information). FIG. 2 refers to this SID/NID pair andassociated cell identification (mobile station network information) as“C”. Without obtaining a position fix, the mobile station device 1000 isable to determine its cell identification and determine whether its cellidentification is on the list of cell identifications in the geofencearea covered by the geofence boundary 420.

In Block 240, the mobile station device 1000 checks to see whether itscurrent SID/NID pair and associated cell identification is included inthe geofence lists of SID/NID pairs and associated cell identifications.FIG. 2 refers to this determination as “C ⊂ G” (i.e., whether C is aproper subset of G).

In Block 240, if “C” is not included in “G”, proceed to block 250. Inblock 250, a skip counter is incremented by one unit. The skip counterkeeps count of the number of times the mobile station networkinformation is not within the geofence network information.

In Block 260, the mobile station device 1000 determines whether the skipcounter is greater than a predetermined threshold Max Skip (e.g., amaximum skip value). In one aspect, if the skip counter is less than orequal to a maximum skip value, the flow may loop back to Block 230 toobtain updated mobile station network information. Alternatively, inanother aspect, the flow may discontinue and delay before reinitiatingby returning to block 230 to obtain updated mobile station networkinformation. Maximum skip value is a predetermined geofence systemparameter that may be configured by the user, the operator or theapplication itself. In one example, the maximum skip value is configuredaccording to the mobile station device's distance from the geofenceboundary 420. One of ordinary skill in the art would understand that themaximum skip value may be configured to delay the mobile station device1000 from obtaining a position fix. In one aspect, maximum skip valuedynamically changes over time. In one aspect, if the skip counter isless than or equal to the maximum skip value, a position report isgenerated that the mobile station device 1000 is not within the geofencearea covered by the geofence boundary 420, but is located within ageographical area covered by the mobile station device's current SID/NIDpair and associated cell identification “C”.

If the skip counter is greater than the maximum skip value, proceed toBlock 270. In Block 270, the mobile station device 1000 calculates a lowQoS (“Quality of Service”) position fix, and provides an outputP(t_(n)). Obtaining a low QoS position fix instead of a high QoSposition fix avoids depleting battery power and using up networkresources. In one aspect, setting a maximum amount of times the mobilestation device 1000 skips before obtaining a low QoS position fix is asafety measure and ensures that the mobile station device 1000 obtainsat least some real position fixes.

In Block 240, if “C” is included in “G”, proceed to block 245. In Block245, “C” is included in “G”. In Block 245, the last real position fixP(t_(n-1)) and previous time t_(n-1) are recovered. The last realposition fix P(t_(n-1)) is the position fix at previous time t_(n-1).

In Block 255, the current time t_(n) is obtained.

In Block 265, the distance radius D_(R) is calculated using V_(n), themaximum velocity of the asset being tracked and the time difference(t_(n)−t_(n-1)) between the current time t_(n) and the previous timet_(n-1). V_(n) is inputted and is assumed to be known. V_(n) is ageofence system parameter that is configured by the user, operator orthe application itself. D_(R) represents the boundary limits of themobile station device's current location. D_(R) is referenced to thelast real position fix P(t_(n-1)). Accordingly, one of ordinary skill inthe art would understand how to determine a geographical area (circle)representing the mobile station's current location. FIG. 3 illustratesan exemplary D_(R) circle A created by D_(R) 350 and the last realposition fix P(t_(n-1)) 360.

In Block 275, the D_(R) circle A is compared with the geofence boundary420. The edge of the geofence boundary 420 is predetermined and isknown. In Block 275, determine whether D_(R) circle A is “far” from thegeofence boundary 420. One of ordinary skill in the art will understandthat the point on D_(R) circle A closest to any given point on thegeofence boundary 420 may be utilized to make this determination. One ofordinary skill in the art will also recognize that in some circumstancesthe point on D_(R) circle A may be closest to more than one point on thegeofence boundary 420.

FIG. 4 shows a mobile station device 1000 in two locations. In onelocation, the mobile station device 1000 is “far” from the geofenceboundary 420. In a second location, the mobile station device 1000 isnot “far” from the geofence boundary 420. A predetermined geofenceboundary threshold Th_(GF) is used to determine whether or not circle Ais “far” from the geofence boundary 420. The relative distance betweenthe geofence boundary 420 and D_(R) circle A determines whether a givenD_(R) circle A is “far” from the geofence edge. The definition of “far”and the predetermined geofence boundary threshold Th_(GF) are decided bythe user, operator or the application itself based on the particulargeofence system and its parameters.

If the D_(R) circle A is determined to be “far” from the geofenceboundary in Block 275, proceed to Block 270. In Block 270, the mobilestation device 1000 calculates a low QoS (“Quality of Service”) positionfix, and provides an output P(t_(n)). Obtaining a low QoS position fixinstead of a high QoS position fix avoids depleting battery power andusing up network resources. In one aspect, following block 270, if a newposition is to be determined, return to block 230 to obtain updatedmobile network information.

If the D_(R) circle A is determined to be not “far” from the geofenceboundary in Block 275, proceed to Block 285. FIG. 4 shows the mobilestation device 1000 in a second location which is not “far” from thegeofence boundary 420. In Block 285, the mobile station device 1000calculates a high QoS (“Quality of Service”) position fix, and providesan output P(t_(n)). A high degree of accuracy is necessary because theuser needs to know an accurate proximity of the mobile station device1000 to the geofence boundary 420. In one aspect, following block 285,if a new position is to be determined, return to block 230 to obtainupdated mobile network information.

From block 285 or block 270, proceed to block 280 where it is determinedif P(t_(n)) is inside the geofence area (i.e., the area defined by thegeofence boundary). If no (not inside), return to block 230. If yes(inside), proceed to block 290 to inform that the mobile station device1000 has entered the geofence area.

FIG. 5 shows one aspect of a position tracking device. In this aspect,the position tracking device 500 comprises a processor 510 withprogrammable instructions for defining a geofence center and a geofenceboundary and for calculating a position fix. Additionally, the positiontracking device 500 includes a receiving unit 520 for receiving geofencenetwork information associated with an area defined by the geofenceboundary, and for receiving mobile station network information. Oneskilled in the art would understand that that in one aspect, portions orthe entire receiving unit 520 are part of the processor 510. In anotheraspect, the receiving unit 520 is a separate component from theprocessor 510. The position tracking device 500 includes a comparatorunit 530 for comparing the mobile station network information to thegeofence network information. One skilled in the art would understandthat in one aspect, portions or the entire comparator unit 530 are partof the processor 510. In another aspect, the comparator unit 530 is aseparate component from the processor 510. In one aspect, the positiontracking device 500 includes a skip counter 540 to keep count of thenumber of times the mobile station network information is not within thegeofence network information. In one aspect, the skip counter 540 may behoused within the processor 510. In another aspect, the skip counter 540is a separate component from the processor 510. One skilled in the artwould understand that the skip counter 540 may be implemented inhardware or in software.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the spirit or scope ofthe disclosure.

The invention claimed is:
 1. A method comprising: defining a geofencecenter and a geofence boundary; receiving geofence network informationassociated with an area defined by the geofence boundary; obtainingmobile station network information; determining whether the mobilestation network information identifies a cell at least partially withinthe geofence boundary; performing an operation when the mobile stationnetwork information does not identify a cell at least partially withinthe geofence boundary, the operation comprising: incrementing a skipcounter, wherein the skip counter is configured to count a number oftimes that the mobile station network information does not identify acell at least partially within the geofence boundary; determiningwhether the skip counter exceeds a threshold representative of a maximumnumber of consecutive times a mobile station device obtaining the mobilestation network information is determined to not be at least partiallywithin the geofence boundary before performing calculations to obtain apseudorange-based low Quality of Service (QoS) position fix using afirst set of parameters; in response to determining that the skipcounter does not exceed the threshold, performing a second operation;and in response to determining that the skip counter exceeds thethreshold, performing operations to calculate a position fix using thefirst set of parameters.
 2. The method of claim 1, further comprisingoutputting the position fix.
 3. The method of claim 2, wherein the firstset of parameters comprises non-satellite positioning system basedpseudoranges.
 4. The method of claim 1, wherein the first set ofparameters comprises non-satellite positioning system basedpseudoranges.
 5. The method of claim 1, wherein the second operationcomprises generating a position report.
 6. The method of claim 1,wherein the second operation comprises: obtaining updated mobile stationnetwork information; and determining whether the updated mobile stationnetwork information identifies a cell at least partially within thegeofence boundary.
 7. The method of claim 1, wherein the threshold isconfigurable.
 8. The method of claim 7, wherein the mobile stationnetwork information relates to the mobile station device and wherein thethreshold is configured based on a distance between the mobile stationdevice and the geofence boundary.
 9. The method of claim 1, furthercomprising determining if the position fix is within the area defined bythe geofence boundary.
 10. The method of claim 9, further comprisingproviding information that the position fix is within the area definedby the geofence boundary.
 11. A method comprising: defining a geofencecenter and a geofence boundary; receiving geofence network informationassociated with an area defined by the geofence boundary; obtainingmobile station network information associated with a mobile stationdevice; determining whether the mobile station network informationidentifies a cell at least partially within the geofence boundary; inresponse to determining that the mobile station network informationidentifies a cell at least partially within the geofence boundary,retrieving a last real position fix of the mobile device and a timeassociated with the last real position fix; calculating a distanceradius based at least in part on the last real position fix and adistance the mobile station device is capable of traveling during a timeperiod, wherein the time period is based on the time associated with thelast real position fix; defining a mobile station boundary that iscentered at the last real position fix based on the distance radius,wherein the mobile station boundary represents a boundary limit of alocation of the mobile station device, wherein the mobile stationboundary is different from the geofence boundary; determining whetherthe mobile station boundary is within a threshold distance from thegeofence boundary; calculating a position fix using quality of serviceparameters based on whether the mobile station boundary is within thethreshold distance from the geofence boundary, wherein the quality ofservice parameters include one of a first set of parameters and a secondset of parameters; incrementing a skip counter value when the mobilestation boundary is not within the threshold distance from the geofenceboundary; comparing the skip counter value with a pre-determinedthreshold value representative of a maximum number of consecutive timesthe mobile station device obtaining the mobile station networkinformation is determined to not be at least partially within thegeofence boundary before performing calculations to obtain apseudorange-based low Quality of Service (QoS) position fix using thefirst set of parameters; and performing operations to obtain new mobilestation network information when the skip counter value exceeds thepre-determined threshold.
 12. The method of claim 11, wherein thequality of service parameters are the first set of parameters when themobile station boundary is not within the threshold distance from thegeofence boundary.
 13. The method of claim 11, wherein the quality ofservice parameters are the second set of parameters when the mobilestation boundary is within the threshold distance from the geofenceboundary.
 14. The method of claim 12, further comprising outputting theposition fix.
 15. The method of claim 13, further comprising outputtingthe position fix.
 16. The method of claim 12, wherein the first set ofparameters comprises non-satellite positioning system basedpseudoranges.
 17. The method of claim 12, wherein the first set ofparameters comprises non-satellite positioning system based pseudorangesfrom at least one of inertial sensors, a mobile switching centeridentification, a code division multiple access zone, a roaming list, anadvanced forward link trilateration, a radio frequency identification,Bluetooth information, and Zigbee system information.
 18. The method ofclaim 13, wherein the second set of parameters comprises satellitepositioning system based pseudoranges.
 19. The method of claim 18,wherein at least one of the satellite positioning system basedpseudoranges is from a pseudolite.
 20. The method of claim 13, whereinthe second set of parameters comprises non-satellite positioning systembased pseudoranges.
 21. The method of claim 11, further comprisingdetermining if the position fix is within the area defined by thegeofence boundary.
 22. The method of claim 21, further comprisingproviding information that the position fix has entered the area definedby the geofence boundary.
 23. A position tracking device comprising: areceiving unit for receiving geofence network information associatedwith an area defined by a geofence boundary and for receiving mobilestation network information associated a mobile device; a comparatorunit for determining whether the mobile station network informationidentifies a cell at least partially within the geofence boundary; askip counter configured to count a number of times that the mobilestation network information does not identify a cell at least partiallywithin the geofence boundary, wherein the skip counter is incrementedeach time that the mobile station network information does not identifya cell at least partially within the geofence boundary; and a processorwith programmable instructions for: defining a geofence center and thegeofence boundary; calculating a position fix; performing an operationwhen the skip counter does not exceed a threshold representative of amaximum number of consecutive times the position mobile device receivingthe mobile station network information is determined to not be at leastpartially within the geofence boundary before performing calculations toobtain a pseudorange-based low Quality of Service (QoS) position fix;and performing a second operation when the skip counter exceeds thethreshold.
 24. The position tracking device of claim 23, wherein theprocessor calculates the position fix using a first set of parameters.25. The position tracking device of claim 23, wherein the programmableinstructions include instructions for recovering a last real positionfix when the mobile station network information identifies a cell atleast partially within the geofence boundary.
 26. The position trackingdevice of claim 25, wherein the programmable instructions includeinstructions for calculating a distance radius based on the last realposition fix and a distance the mobile station device is capable oftraveling during a time period and defining a mobile station boundarythat is centered at the last real position fix, wherein the mobilestation boundary represents a boundary limit of a location of a mobilestation device, wherein the mobile station boundary is different fromthe geofence boundary.
 27. The position tracking device of claim 26,wherein the programmable instructions include instructions fordetermining if the mobile station boundary is within a thresholddistance from the geofence boundary.
 28. The position tracking device ofclaim 27, wherein the processor calculates the position fix using afirst set of parameters if the mobile station boundary is not within thethreshold distance from the geofence boundary.
 29. The position trackingdevice of claim 27, wherein the processor calculates the position fixusing a second set of parameters if the mobile station boundary iswithin the threshold distance from the geofence boundary threshold. 30.A non-transitory computer-readable medium including program code storedthereon, comprising program code to: define a geofence center and ageofence boundary; receive geofence network information associated withan area defined by the geofence boundary; obtain mobile station networkinformation associated with a mobile device; determine whether themobile station network information identifies a cell at least partiallywithin the geofence boundary; increment a skip counter in response todetermining that the mobile station network information does notidentify a cell at least partially within the geofence boundary, whereinthe skip counter is configured to count a number of times that themobile station network information does not identify a cell at leastpartially within the geofence boundary; determine whether the skipcounter exceeds a threshold representative of a maximum number ofconsecutive times the mobile device obtaining the mobile station networkinformation is determined to not be at least partially within thegeofence boundary before performing calculations to obtain apseudorange-based low Quality of Service (QoS) position fix using afirst set of parameters; perform a second operation in response to theskip counter not exceeding the threshold; and perform operations tocalculate a position fix using the first set of parameters in responseto the skip counter exceeding the threshold.
 31. A non-transitorycomputer-readable medium including program code stored thereon,comprising program code to: define a geofence center and a geofenceboundary; receive geofence network information associated with an areadefined by the geofence boundary; obtain mobile station networkinformation associated with a mobile device; determine whether themobile station network information identifies a cell at least partiallywithin the geofence boundary; recover information associated with a lastreal position fix of the mobile station device when the mobile stationnetwork information identifies a cell at least partially within thegeofence boundary; calculate a distance radius based at least in part onthe last real position fix and a distance the mobile station device iscapable of traveling during a time period; define a mobile stationboundary that is centered at the last real position fix based at leastin part on the distance radius, wherein the mobile station boundaryrepresents a boundary limit of a location of a mobile station device,wherein the mobile station boundary is different from the geofenceboundary; determine whether the mobile station boundary is within athreshold distance from the geofence boundary; calculate a position fixusing quality of service parameters based on whether the mobile stationboundary is within the threshold distance from the geofence boundary;incrementing a skip counter value when the mobile station boundary isnot within a threshold distance from the geofence boundary; comparingthe skip counter value with a pre-determined threshold valuerepresentative of a maximum number of consecutive times the mobiledevice obtaining the mobile station network information is determined tonot be at least partially within the geofence boundary before performingcalculations to obtain a pseudorange-based low Quality of Service (QoS)position fix; and performing operations to obtain new mobile stationnetwork information when the skip counter value exceeds thepre-determined threshold.
 32. An apparatus comprising: means fordefining a geofence center and a geofence boundary; means for receivinggeofence network information associated with an area defined by thegeofence boundary; means for obtaining mobile station networkinformation; means for determining whether the mobile station networkinformation identifies cell at least partially within the geofenceboundary; means for performing an operation when the mobile stationnetwork information does not identify a cell at least partially withinthe geofence boundary, the operation comprising: incrementing a skipcounter, wherein the skip counter is configured to count a number oftimes that the mobile station network information does not identify acell at least partially within the geofence boundary; determiningwhether the skip counter exceeds a threshold representative of a maximumnumber of consecutive times the apparatus obtaining the mobile stationnetwork information is determined to not be at least partially withinthe geofence boundary before performing calculations to obtain apseudorange-based low Quality of Service (QoS) position fix using afirst set of parameters; in response to determining that the skipcounter does not exceed the threshold, performing a second operation;and in response to determining that the skip counter exceeds thethreshold, performing operations to calculate a position fix using thefirst set of parameters.
 33. The apparatus of claim 32, furthercomprising means for outputting the position fix.
 34. The apparatus ofclaim 33, wherein the first set of parameters comprises non-satellitepositioning system based pseudoranges.
 35. An apparatus comprising:means for defining a geofence center and a geofence boundary; means forreceiving geofence network information associated with an area definedby the geofence boundary; means for obtaining mobile station networkinformation associated with a mobile station device; means fordetermining whether the mobile station network information identifies acell at least partially within the geofence boundary; in response todetermining that the mobile station network information identifies acell at least partially within the geofence boundary, means forretrieving a last real position fix of the mobile device and a timeassociated with the last real position fix; means for calculating adistance radius based at least in part on the last real position fix anda distance the mobile station device is capable of traveling during atime period, wherein the time period is based on the time associatedwith the last real position fix; means for defining a mobile stationboundary that is centered at the last real position fix based on thedistance radius, wherein the mobile station boundary represents aboundary limit of a location of the mobile station device, wherein themobile station boundary is different from the geofence boundary; meansfor determining whether the mobile station boundary is within athreshold distance from the geofence boundary; means for calculating aposition fix using quality of service parameters based on whether themobile station boundary is within the threshold distance from thegeofence boundary, wherein the quality of service parameters include oneof a first set of parameters and a second set of parameters; means forincrementing a skip counter value when the mobile station boundary isnot within a threshold distance from the geofence boundary; means forcomparing the skip counter value with a pre-determined threshold valuerepresentative of a maximum number of consecutive times the mobilestation device obtaining the mobile station network information isdetermined to not be at least partially within the geofence boundarybefore performing calculations to obtain a pseudorange-based low Qualityof Service (QoS) position fix using the first set of parameters; andmeans for performing operations to obtain new mobile station networkinformation when the skip counter value exceeds the pre-determinedthreshold.